/Engine/Source/Runtime/CoreUObject/Public/UObject/UObjectGlobals.h
Called as last phase of reachability analysis. Allow external systems to addUObjectrootsafterfirst reachability pass has been done
static [FTraceExternalRootsForReachabilityAnalysisDelegate](API\Runtime\CoreUObject\UObject\FCoreUObjectDelegates\FTraceExternalRo-) TraceExternalRootsForReachabilityAnalysis;